Prostatic stent with localized tissue engaging anchoring means and methods for inhibiting obstruction of the prostatic urethra

Abstract

A prostatic stent is configured as a unitary body, which is adapted to reside above the sphincter when in position in a subject and allow normal functioning of the sphincter. The stent includes and elongated and substantially narrow conduit, which extends through the sphincter and outside the body of the subject. The conduit is sized and constructed to allow normal operation of the sphincter. The stent also includes and upper and/or an intermediate inflatable portions and may include a second conduit for the introduction of medication to the stent.

That which is claimed is:  
     
       1. A prostatic stent configured for insertion into the urethra of a male subject, the urethra generally including, in serial order from the externalmost portion to the internal portion, the penile meatus, the penile urethra, the bulbous 
       urethra, the sphincter, the membranous urethra, the prostatic urethra, the bladder neck and the bladder, said prostatic stent comprising:  
       a unitary tubular body having a central lumen extending therethrough and a first cross-sectional width thereacross;  
       a tissue-engaging inflatable balloon positioned on a lower perimeter portion of said unitary body; and  
       at least one conduit having opposing upper and lower end portions with a fluid lumen formed therein, a portion of said upper end attached to said unitary tubular body such that it is in fluid communication with said inflatable balloon, said conduit having a second cross-sectional width, the second cross-sectional width being less than said first cross-sectional width;  
       wherein, in position in the subject, said stent is configured such that said unitary body resides above the sphincter and said conduit extends through the sphincter and out of the penile meatus of the subject, and wherein said conduit is sized and constructed such that it allows substantially natural closing of the sphincter when in position in the subject.  
     
     
       2. A prostatic stent according to  claim 1 , wherein said unitary tubular body is configured such that a contiguous major portion of the length of said body is non-inflatable, and wherein said contiguous major portion is located above said inflatable tissue engaging anchoring balloon. 
     
     
       3. A prostatic stent according to  claim 1 , further comprising an upper anchoring balloon disposed about an upper portion of said unitary tubular body. 
     
     
       4. A prostatic stent according to  claim 1 , wherein a selected one of said at least one conduits is releasably attached to said unitary tubular body such that it can detached in situ from the stent by pulling on an end portion of said conduit without dislodging the unitary body from a desired location in the subject, and wherein said selected releasably attached conduit is configured to be readily visually identified externally when said stent is in position in the subject. 
     
     
       5. A prostatic stent according to  claim 1 , further comprising an intermediately positioned tissue-molding balloon disposed about said unitary tubular body. 
     
     
       6. A prostatic stent according to  claim 1 , wherein said unitary tubular body is sufficiently conformable to yield to the contours of the subject's body as it is inserted therein, yet sufficiently rigid to provide an open lumen when in position in the prostate and exposed to prostatic tissue which is exhibiting distress subsequent to undergoing thermal ablation therapy. 
     
     
       7. A prostatic stent according to  claim 1 , wherein at least one of said at least one conduits is configured with externally visible indicia of movement. 
     
     
       8. A prostatic stent according to  claim 1 , wherein said unitary body has a length which is about 4-10 cm. 
     
     
       9. A prostatic stent according to  claim 1 , wherein said unitary tubular body includes a pair of spaced apart walls which are configured to define at least one fluid flow channel therebetween. 
     
     
       10. A prostatic stent according to  claim 1 , wherein said unitary body has opposing upper and lower ends, wherein said upper end is configured to enter a distance into the bladder, and wherein said upper end is open. 
     
     
       11. A prostatic stent according to  claim 2 , Wherein a series of spatially separate apertures are formed in said unitary tubular body and arranged about the perimeter of a portion of said upper end, and wherein said apertures are in fluid communication with said central lumen. 
     
     
       12. A prostatic stent according to  claim 3 , wherein said unitary tubular body has opposing upper and lower ends, wherein said upper end is configured to enter a distance into the bladder, and wherein said upper end is closed, and wherein said stent body further comprises a urinary drainage port in fluid communication with said central lumen and disposed longitudinally spaced apart from said closed end in a direction which is toward said lower end of said unitary body, and wherein said conduit comprises a region with increased elasticity intermediate said tissue engaging balloon and said upper anchoring balloon. 
     
     
       13. A prostatic stent according to  claim 1 , wherein said at least one conduit includes two conduits. 
     
     
       14. A prostatic stent according to  claim 13 , wherein said two conduits are in fluid communication. 
     
     
       15. A prostatic stent according to  claim 13 , wherein said two conduits are in fluid isolation. 
     
     
       16. A prostatic stent according to  claim 1 , wherein said tissue engaging inflatable balloon is configured when expanded such that it has a profile which tapers to increase in width from top to bottom. 
     
     
       17. A prostatic stent according to  claim 1 , further comprising an externally visible indicia of the inflation status of said tissue-engaging inflatable balloon. 
     
     
       18. A prostatic stent according to  claim 1 , wherein said stent tubular body is configured with a hydrophilic lubricant. 
     
     
       19. A prostatic stent according to  claim 1 , wherein said stent tubular body is configured with an antimicrobial agent. 
     
     
       20. A set of prostatic stents each configured for insertion into the urethra of a male subject, the urethra generally including, in serial order front the external most portion to the internal portion, the penile meatus, the penile urethra, the bulbous urethra, the sphincter, the membranous urethra, the prostatic urethra, the bladder neck and the bladder, said set of prostatic stents-comprising: 
       (a) a first prostatic stent comprising:  
       a unitary tubular body having a central lumen extending therethrough, a first length, and an associated cross-sectional width thereacross;  
       a tissue engaging inflatable balloon positioned on a lower perimeter portion of said unitary body; and  
       at least one conduit having opposing upper and lower end portions with a fluid lumen formed a portion of said upper end attached to said unitary tubular body such that it is in fluid communication with said inflatable balloon, said conduit having a second cross-sectional width, the second cross-sectional width being substantially less than said first cross-sectional width;  
       (b) a second prostatic stent comprising:  
       a unitary tubular body having a central lumen extending therethrough, a second length and an associated cross-sectional width thereacross;  
       a tissue engaging inflatable balloon positioned on a lower perimeter portion of said unitary body; and  
       at least one conduit having opposing upper end lower end portions with a fluid lumen formed therein, a portion of said upper end attached to said unitary tubular body such that it is in fluid communication with said inflatable balloon, said conduit having a second cross-sectional width, the second cross-sectional width being substantially less than said first cross-sectional width,  
       wherein, in position in the subject, each of said stents is configured that said unitary body resides above the sphincter and said conduit extends through the sphincter and out of the penile meatus of the subjection, and wherein said conduit is configured such that it allows substantially,natural closing of the sphincter when in position in the subject, and further wherein said first stent unitary body has a different length than said second stent unitary body.  
     
     
       21. A set of prostatic stents according to  claim 20 , wherein said conduits of said first and second stents comprise a series of externally visible graduation marks thereon. 
     
     
       22. A prostatic stent configured for insertion into the urethra of a male subject, the urethra generally including, in serial order from the externalmost portion to the internal portion, the penile meatus, the penile urethra, the bulbous urethra, the sphincter, the membranous urethra, the prostatic urethra, the bladder neck and the bladder, said prostatic stent comprising: 
       a unitary tubular body having a central lumen extending therethrough and a first cross-sectional width thereacross;  
       a tissue-engaging inflatable balloon positioned on a lower perimeter portion of said unitary body; and  
       at least one conduit having opposing upper and lower end portions with a fluid lumen formed therein, a portion of said upper end attached to said unitary tubular body such that it is in fluid communication with said inflatable balloon, said conduit having a second cross-sectional width the second cross-sectional width being less than said first cross-sectional width; and  
       wherein at least one conduit is releasably attached to said unitary tubular body such that it can be detached in situ from the stent by pulling on an end portion of said conduit without dislodging the unitary body from a desired location in the subject; and  
       wherein, in position in the subject, said stent is configured such that said unitary body resides above the sphincter and said conduit extends therethrough the sphincter and out of the penile meatus of the subject, and wherein said conduit is sized and constructed such that it allows substantially natural closing of the sphincter when in position in the subject;  
       wherein a selected one of said at least one conduits is releasably attached to said unitary tubular body such that it can detached in situ from the stent by pulling on an end portion of said conduit without dislodging the unitary body from a desired location in the subject, and wherein said selected releasably attached conduit is configured to be readily visually identified externally when said stent is in position in the subject.